On two different i386 -current systems (from yesterday and the day
before) I get reliably
...

fwohci0 at pci5 dev 8 function 0: NEC product 0x00e7 (rev. 0x01)
fwohci0: interrupting at ioapic0 pin 19 (irq 5)
fwohci0: OHCI version 1.10 (ROM=1)
fwohci0: No. of Isochronous channels is 4.
fwohci0: EUI64 00:00:4c:01:07:00:0e:bf
fwohci0: Phy 1394a available S400, 2 ports.
fwohci0: Link S400, max_rec 2048 bytes.
ieee1394if0 at fwohci0: IEEE1394 bus
fwip0 at ieee1394if0: IP over IEEE1394
fwohci0: Initiate bus reset
fwohci0: node_id=0xc000ffc0, gen=1, CYCLEMASTER mode

...
fwohci0: node_id=0x8000ffc0
ieee1394if0: 2 nodes, maxhop <=1, cable IRM = 0 (me)
ieee1394if0: root node is not cycle master capable
ieee1394if0: bus manager 0 (me)
ieee1394if0: New S400 device ID:0090a992e0000001
fwohci0: too many cycles lost, no cycle master presents?
sbp0 at ieee1394if0: SBP-2/SCSI over IEEE1394
scsibus1 at sbp0: 1 target, 0 luns per target
sbp0:0:0 request timeout(cmd orb:0x01a660d4) ... agent reset
uvm_fault(0xc0a7d040, 0, 2) -> 0xe
kernel: supervisor trap page fault, code=0
Stopped in pid 0.2 (system) at netbsd:scsipi_periph_freeze+0x1e: addl
%esi,0x4c(%ebx)
db{0}> bt
scsipi_periph_freeze(0,1,c062f0a0,c1678400,c044207c) at
netbsd:scsipi_periph_freeze+0x1e
sbp_timeout(cc6d00c8,1,cafefc04,c0a8162c,c16cdd20) at netbsd:sbp_timeout+0x123
softclock(0,c0100bda,4,0,c0100bda) at netbsd:softclock+0x261
softintr_dispatch(0,cafefc08,0,0,0) at netbsd:softintr_dispatch+0x90
DDB lost frame for netbsd:Xsoftclock+0x3a, trying 0xcb07bff4
Xsoftclock() at netbsd:Xsoftclock+0x3a
--- interrupt ---
0:
db>{0}

when I connect Western Digital MyBook 500GB triple i/f (S800, S400,
USB2) to IEEE1394 bus (S400). It works fine using USB i/f. I managed
to get a dump, in case someone is interested. This is using GENERIC.MP
(+ some slight mods on the laptop - basically, DRM).

I've got another IEEE1394 disk which works fine on the same machines.

Chavdar Ivanov